Searching for the missing pieces of climate change communication

Tag Archives: Falsifiability

The hyperbole level was high in this news item from the VTM news of last Saturday: Fifty Times More Deaths By Weather. This is how it is introduced (translated from Dutch):

South and Central Europe are moaning under a heatwave these days and this has consequences. In Italy, for example, is it up to 46 degrees and there are already three deaths. It is an example of what will happen much more by the end of this century: people who die from extreme weather. That is what researchers of a working group of the European Commission say. According to their study, there will be about 152,000 deaths by weather-related phenomena per year between 2071 and 2100, mainly caused by climate change.

Since about six months the Belgian newspaper Het Laatste Nieuws (The Latest News), seemed to be slowing climate alarmism. I first noticed this when reading their reporting on Haiyan. The reporting on it was surprisingly balanced. But yesterday they apparently couldn’t resist. They wrote an article about our warm winter and warm spring that we are experiencing now, interviewing their (alarmist) weatherwoman (from their paper edition, translated from Dutch):

[…] The weather has lost its bearings. According to official KMI terminology, it is ‘abnormally’ warm now for already five months. And except for February there was also much less rainfall than normal since December. […]
“It is no longer news that the earth is warming”, said Jill Peeters, our weatherwoman. “But when you see these numbers, then it is only becoming clearer. The average temperatures used by KMI, are over the past thirty years. If you were to compare with the start of the measurements, then the differences would be even more extreme”. […]

What happened to global warming? Belgium is roughly a whopping 0.006% of the earth. I have to admit that there are more countries than Belgium with this weather, but she forgot to mention for example the United States, where they had their coldest winter. If our warm winter is some kind of evidence that the earth is warming, why is the current cold winter in the United States or our “winter that never ended” just from last year, not evidence that the theory is not coping well? She has no problem with that (translated from Dutch):

The earth is warming up, but within that upward trend there will always be variability.

Here you have it. When it is a warm winter, apparently it is more evidence of global warming. When it is a cold winter, it is just natural variability… In that sense global warming can never be falsifiable and is always true. No matter what the observations are.

I agree that the temperatures rose in the last thirty years and even more in the last 160 years. But this doesn’t necessarily means that humans were the primary cause or that it is catastrophic in nature. It could as well be a recovery from the Little Ice Age. Looking at the longer term datasets cycles of about 60 years become visible. So her definition of 30 years for climate is only a measly half of one cycle, more specifically the upwards part of it. When one takes the satellite dataset (that should be the most accurate globally) temperatures didn’t rise much from the end of the 1970s on and it didn’t rise at all for a decade and a half now. Although we pumped an unprecedented amount of CO2 in the atmosphere during that period.

That would let the temperature rise dangerously.

By 2100.

Or so.

There seemingly wasn’t enough hyperbole until that point in the article. This is how she concludes (translated from Dutch):

The weatherwoman hopes that the weather makes a jump again. “And I’m talking mostly about the drought. If the coming months bring so little rain, then we really will really suffer a long heat wave. We should not hope for that. Nature is in full bloom, but therefor she needs plenty of water, and there is too little of that now.

While it had rained less than normal in most of those months it is not that it didn’t rain. She said that “except for February there was much less rain than normal since December”. This gives the (false) impression that it was much too dry in this period (except for one month). This is her own data:

Month

Average (mm)

Precipitation (mm)

December 2013

81

77.1

January 2014

76.1

70.1

February 2014

63.1

66.2

March 2014

70

18

April 2014

51.3

20.1

December 2013 and January 2014 were slightly below average, February 2014 was above average and only the two last months rainfall were well below average (before that, November 2013 was extremely wet, almost doubling the average for that month).

A couple months with below average rainfall is nothing special in Belgium. It happened before, it certainly will happen again. That is what averages are. Sometimes less, sometimes more. By the way, most projections for Belgium are about more precipitation in the future and we are told to worry about that. Now we should start worrying about droughts in the future too? Unless climate is changing within the time span of a couple months, the chance that this “drought” will last for long is very small. Even before her article went to press, a rain zone crossed our country and even more rain is forecasted for next week. So much for the drought.

I remember vividly the times that global warmers were saying that “weather is not climate” when they got stuck for an explanation. Now they even have to resort to the variability of weather to make their case…

When listening to the alarmists panel in the UK Parliamentary Inquiry on the science of IPCC AR5, I noticed a clear difference to the skeptics panel. The witnesses in the alarmists panel were very sure about themselves. The science was clear. There was a consensus. Climate scientists were skeptical themselves and keeping science sane. There is uncertainty, but it is small and is accounted for. The models were reliable and could give valuable answers. They said all those things with much confidence.

How could there be such a large contrast with the skeptical panel? I think it certainly has to do with the role they are playing. As John Robertson said:

I like the idea that science tells us something and we have to agree because science says that is it.

Some sites made fun of this statement of John Robertson, but I think it is right in the heart of the issue. The politicians like simplicity from scientists. They like them to say if global warming is really happening, yes or no. If it changes our climate. If there is a need for action and what that right action then should be. There is no shame admitting that. For several decades now we are being told an extremely simple story:

It is simple and straight forward. So we also expect the same confidence from those who study it. They are considered the experts. This means they could not possibly backpedal now and say there are still huge uncertainties, that the models were way of with reality. That is what the skeptics are saying and it doesn’t serve them well. Therefor they avoid the inconvenient parts like the standstill in temperatures, the many uncertainties they face, the failing models,…

Let’s face it. People are attracted to confident statements from those they consider the experts. This is how issues are communicated most efficiently. That’s why the “consensus” is so important and alarmists put a lot of effort into declaring it. It is not because it is part of the scientific methods or important in science. It is because people, especially those who don’t want to look into the issue, are biased to the side of the largest group. Thinking that “They can’t all be wrong”.

But isn’t that a problem for the scientists involved? Sure, it is. If their predictions/forecasts/projections don’t materialize, they lose credibility. But the projections are way ahead in the future. Many of the projections of the IPCC are for 2100, more than 80 years ahead of us. There is no doubt all the current experts will be long gone before any of those predictions can be verified or falsified. So at this point it doesn’t even matter what they project.

But shouldn’t we respect our experts? Sure, but we should keep being skeptical, especially in areas where there is little data and high uncertainties. The fact that scientists try to declare a consensus and high certainty in a complex system with little data should be a clear warning sign.

The alarmists panel in the inquiry knew what was being expected from them. They delivered. They likely will be asked again.

There was lots of talking about the polar vortex this week. Even in this tiny country, which wasn’t affected by the freezing temperatures (yet), the media was full of the polar vortex that made the freezing temperatures in Northern America possible. The media was assuring us that this cold snap was the result of global warming (but a lot carefully avoided calling it global warming and diplomatically called it climate change).

This is basically how the media said it works: it is the result of the rapid melting of Arctic sea ice because of climate change. This decreases the albedo of the Arctic region and as a result it heats up faster than other parts of the Earth. The temperature difference between the Arctic and the southern regions determines the strength of the jet stream. If the jet stream is strong, it isolates the cold Arctic from the warmer mid latitudes. But because of this melt the jet stream becomes weaker and more wavy, allowing cold air (usually confined to the poles) to reach further into the mid latitudes. Et voilà, global warming/climate change caused the severe cold snap. John Holdren, the science advisor of President Obama, even went that far to state that because of this process those deep freeze cold snaps will occur more frequent in the future.

But in general, I can agree with the statement that current cold wave doesn’t disprove global warming. Yet, while it is a nice explanation of the assumed mechanism, it doesn’t prove global warming either. It only proves that media and scientists are creative in finding new ways to fit new events into the theory. AFTER the facts, that is. That’s not difficult, that is what humans are good at, finding connections between seemingly unconnected things.

But deep freeze winters due to the weakening of the jet stream is nothing new. In the 1970s it was used to explain the coming of a new ice age. Younger people may think the weather we see now is unprecedented, but it is not that extreme, nor unprecedented when looking at it over a larger time frame. Remove the hype and there is not much of a story left. Holdren, as a crusader of the coming new Ice Age in the 1970s, should at least recognize that.

How much of this is due to anthropogenic causes? The theory seem to rely on polar amplification. That is a real process, but it doesn’t prove anything about the anthropogenic nature of the warming. Any warming would have that effect, whether it is natural, anthropogenic or both. By the way, the outbreak of cold is also part of the negative phase of the Northern Atlantic Oscillation, which is a natural pattern.

To me it seems yet another patch on a wound of a heavily bruised theory that continue to limp further. I didn’t hear anything about having a higher frequency of very cold winters as a result of global warming/climate change until recently. On the contrary. I heard a lot about more heatwaves, higher temperatures at night, more droughts, more storms, less to no snow,… sure, but very cold winters? No. When it started to snow massively in 2010, suddenly snow became a result of global warming or at least not impossible in a warming world. It seems the same with the cold winters due to the melting ice. Just adding to the possible explanations and covering an additional hole without elimination other ones.

I would be more impressed if scientists came with new falsifiable hypotheses/predictions (based on the global warming theory) about these snowy winters. Now we only hear after the facts that this is not impossible in a warming world or doesn’t disprove global warming. Which is not a big deal actually.

In previous post I concluded with the remark that probability theories are not falsifiable in a strict true|false way, but they can be seen as competing theories that can be compared. The theory that makes the clearest predictions of future outcome and that describes best previous and current observations, will be more preferable. Maybe this was a bit an abrupt ending, so I will explain a bit more in this post. Especially the Global Warming theory against one competing theory: the Natural Cycle theory.

First, let’s look at some long term measurements of temperatures. Below the Giss dataset, starting from 1880 (figure 1).

I will accentuate some trends on this graph to explore the two theories. The lines were made with a simple graphic editor, so they don’t pretend high accuracy. They are drawn to give some indication of trends or, more accurate, how trends are perceived.

The global warming theory

The Global Warming Theory claims that we put ever increasing amounts of CO2 from burning fossil fuel in the atmosphere. CO2, being a greenhouse gas is the major driver for the temperature increase. It is a plausible theory and can explain a lot. At first glance one could easily deduce that man and industrialization has caused global warming (figure 2). It explains the increase of temperatures, especially the warming at the end of the 20th century (which is perfectly in line with the CO2 increase at that time).

Figure 2: Representing Global Warming

But it doesn’t explain very well the warming in the first half of the 20th century. There was not much CO2 added in the atmosphere yet (CO2 started to pick up speed in the second half of the century), so this warming supposed to be of natural cause. But after this the temperature was decreasing or stayed the same when more CO2 was “spewed” in the atmosphere. Compared the warming of the first half to the warming of the second, which has the same increase (figure 3), but this time it is supposed to be primarily of anthropogenic cause.

Figure 3: Parallel warming begin and end 20th century

It also doesn’t explain very well the stagnation of the last 10+ years in which there was more CO2 in the atmosphere than ever before. If CO2 is the major driver of the temperature increase this stagnation doesn’t fit very well. In that case one would expect there is a driver (or a set of drivers) that is as strong as CO2.

The natural cycles theory

The Natural Cycle theory claims that the earth is warming and cooling in cycles. There are cycles of about 30 years, but there are also other cycles that are longer, like 300-500 years. The last one was called Little Ice Age (of about 500 years) and followed the Medieval Warm period (of about 400 years).

Figure 4: Representing Cycles

When one looks at the graph from 1880, the temperature doesn’t increases gradually, but one can see regular shifts in which there are increases followed by decreases or stagnations (figure 4). It explains the cooling until the 1910s, the next 30 years a warming, the next 30 years a small decrease/stagnation, the next 30 years a warming. Next, according to the theory the current stagnation should not be a surprise at all and even could last for some decades.

More questions

But doesn’t CO2 has an effect then? Of course it does. As a greenhouse gas, everything else being equal, it will give some warming if there is more of it. But it is not necessarily the major driver as assumed in the Global Warming theory.

But doesn’t the graph show a large upward trend? The upward parts are way larger than the downward/stagnation parts. True, but this probably has more to do with the scale of the Y-axis. Expand the scale and warming will seem to go trough the roof. Compress it and the warming will seem unimpressive.

But what about the increase itself? According to the graph there is an temperature increase of about 0.8 °C over the last 130 years. Isn’t that reflecting the industrialization of our society? Could well be, but we came out of a cold period around 1850 (end of the Little Ice Age). If the last large (cold) cycle was about 500 years in length, then a 130 year of warming shouldn’t be that unusual…

To end

Of course this doesn’t prove anything. But it gives an indication that the recorded warming can be explained otherwise or, well, let’s say is also “consistent with” other theories. The global warming theory is not the only theory that can explain the temperature increase in the last 130 years. It shows that there is at least one other competing theory that is plausible and can be used to compare.

Advertisements

Like this:

In previous post Snow, a thing of the past I explored the positions of both sides of the debate concerning the connection between snow and global warming. One thing I didn’t touch yet was the skeptics’ remark that “One can not have it both”. There were statements before that snow was a thing of the past because of global warming, but now when snow falls in abundance, there is the statement this is also because of global warming. If this is the case, it can not be proven right nor wrong.

By their nature, skeptics are, well… skeptical. They want testable statements that can prove or disprove something. This is rooted in science and is called falsifiability. In the most simplest way it looks like this: a hypothesis (testable statement) must predict at least one observation by which it can be refuted. If the evidence is in line with the prediction, the statement may be right. If the evidence conflicts with the prediction, the statement is wrong.

Maybe a bit theoretical, so an example to make it clear. Let’s suppose the statement: “All ravens are black”. It can be made testable by stating that if all ravens are black, this means no raven with another color will exist.

If we find a white raven, then the statement “All ravens are black” is clearly wrong: it is falsified (proven to be false)

If we see only black ravens, then the statement might be right. “Might” because there is always the possibility that we just didn’t find the ones with another color. They could exist, even if we didn’t find them (yet).

By the way, white ravens do exist (although they are rare).

This is a very simple example and it should be nice if this was also applicable to global warming. The reality is not always that simple. Predicting something is hard, especially about the future. Especially about a complex thing like the climate. So statements about global warming will be stated in a less clear manner. Something like: “it will be more likely”, “it might” or “it is unlikely”. These are all stated as a probability.

One problem: statements based on probability are not falsifiable by default. This is not difficult to understand: suppose one has the statement It is very likely that the frequency of heavy precipitation events will increase. Suppose we define very likely as more than 90% chance. What happens when we test the precipitation in certain places over a certain time?

If we find an increase in heavy precipitation, the statement might be true.

If we find a decrease in heavy precipitation, the statement isn’t necessarily false. There is a possibility of at least 90% of an increase, but this also means a possibility of up to 10% equal or a decrease in heavy precipitation. It might even be possible that the precipitation was measured in a different place where the increase was not observed. Or maybe the time frame wasn’t long enough to be able to see the increase.

In conclusion, even if the outcome is not consistent with the statement, it doesn’t falsify it.

Of course, first the meaning of increase in frequency and heavy precipitation and probably also the time frame have to be defined. If not, the statement is almost meaningless and one could prove about everything.

This seems disturbing. Does this means that many of the global warming statements can’t even be falsified? I was puzzled about this for a long time. Now I think it is not necessarily true. In the real world we realize that falsifiability is important, but not the only thing being taken into consideration.

Suppose a probability statement that eventually fails. As we saw this doesn’t mean the statement is false, but it doesn’t exactly add to the credibility of the statement and those who make it. The higher the probability with which the statement was stated, the more credibility loss. It is not surprising at all to see fading confidence if observations are not in line with what one would expect from the theory.

A non falsifiable statement looks like a horrible thing when trying to prove or disprove something. But look at it from the other side: a probability statement has, well…probability. Snow and heavy precipitation are consistent with the theory of global warming, but they are also consistent with other things. There isn’t necessarily just one theory. By the fact the theory has to be proved by probability statements, there will be at least one competing theory, maybe even more. All with their own probabilities, explanation of previous observations and predictive value.

This post started with the remark “One can not have it both”. Well, can it? Of course not. At least not in the sense of piling up statements so a theory will be confirmed with any observation possible. That would be the same as stating that “All ravens are black, except when they are not”. This doesn’t learn us nothing new, the predictive value of this is exactly zero.

It is easy to come with an explanation after the facts. The real test is how a theory predicts data we haven’t seen yet and also describes previous and current observations best. This doesn’t necessarily means falsification in a strict true|false way as we would expect with the “One can not have it both”-remark. But rather a comparison between competing theories.